Motor vehicle seats typically include a head restraint pad mounted to the seat for comfort and safety of the passenger. The head restraint pad is mounted on one or two posts which are inserted into guide sleeves affixed to the seat. The posts typically include retainer notches which allow the head restraint pad to be vertically adjustable.
U.S. Pat. No. 4,854,642 to Hoover Universal, Inc., discloses a head restraint guide assembly having a bushing member installed within the seat back for receiving the head restraint pad posts. The head restraint bushing includes extending legs with ramp surfaces so that when the bushing is inserted within the seat back the legs are resiliently deflected and become locked into place when the installed position is reached. The head restraint post passes through the bushing and has a number of notches which provide detents. A detent lug carried by the bushing engages the detent notches and is resiliently biased against the post. The detent notches are provided with cam surfaces enabling the head restraint to be raised and lowered to and past the detent positions. The lowermost notch forms a retainer notch with a radial wall which prevents complete removal of the head restraint. A leaf spring actuator is used which can be depressed from outside of seat back and acts on the detent lug to deflect it out of engagement with the detent notches, thereby enabling withdrawal of the head restraint assembly.
In order to remove the head restraint post, a downward force must be applied to the actuator by a tool such as a screwdriver, causing the lug to move out of engagement with the retainer notch. Additionally, once the bushing member is inserted into the seat, it is not removable.